A workpiece processing apparatus including a control unit that is provided with a storage medium on which a polishing load measured when an upper turn table is moved downward to a fixed position in a state wherein the workpiece is properly held in holding hole of the carrier is recorded in advance, calculates a difference between a polishing load measured when upper turn table is moved downward to the fixed position in a state wherein the workpiece is held in holding hole of the carrier and the polishing load recorded on the storage medium, and judges the occurrence of abnormal holding of the workpiece if the calculated difference exceeds a threshold value. As a result, it becomes possible to detect abnormal holding of a workpiece in a short time with a high degree of precision before the workpiece is processed and prevent breakages of the workpiece and the processing apparatus.